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With the increasing of wind energy, it is necessary to develop an energy storage system to level the wave of wind power, and to develop a fault current limiter for improvement of the LVRT capability of the wind farm. An innovative idea to deal with the above problem is to develop a superconducting fault current limiter-magnetic energy storage system (SFCL-MES). In this paper, we report the progress of the superconducting coil for a 1-MJ/0.5-MVA FCL-SMES system. The coil consisted of 46 double pancakes, in which 8 pancakes were made of YBCO tapes and the others were made of Bi2223 tapes; the inductance of the coil was 13.3 H, and its rated current was 388 A while the maximum magnetic field was 3.5 T. This coil had been used for a FCL-SMES system, which was installed and tested at a wind farm connected to the live power grid. [ABSTRACT FROM AUTHOR]

The ground state of K0.8+xFe1.6+ySe2 and other iron-based selenide superconductors are doped antiferromagnetic semiconductors. We propose that the low energy physics of this system is governed by a model Hamiltonian of interacting electrons with onsite ferromagnetic exchange interactions and intersite superexchange interactions. We have derived the effective pairing potential of electrons under the linear spin-wave approximation and shown that the superconductivity can be driven by mediating coherent spin-wave excitations in these materials. Our work provides a natural account for the coexistence of superconducting and antiferromagnetic long range orders observed by neutron scattering and other experiments. [ABSTRACT FROM AUTHOR]

Magnesium diboride (MgB2) shows a wide application prospect in the field of low field DC application for its relatively simple structure and rather higher critical temperature than LTS. With the development of MgB2 composite superconductor manufacturing technology and cryogenic technology, developing conduction cooled superconducting MRI system with MgB2 composite superconductor is becoming increasingly feasible. An MgB2 superconducting magnet for MRI was developed. The MgB2 superconducting magnet is used to investigate the fundamental scientific problem of the MRI main magnet, including field uniformity and stability, influencing factors of MgB2 composite superconductor on field uniformity and stability. The superconducting magnet consists of 2 solenoids wound with MgB2 wire with the length of 60 m. The magnet has an outer diameter of 169 mm, an iron core diameter of 135 mm, and air gap of 32 mm. The superconducting magnet is fabricated and tested. The central magnetic field reaches 1.0 T when the current of the MgB2 magnet is 290 A. The central magnetic field is 0.39 T when the current of the MgB2 magnet is 100 A. In this paper, main magnet for MRI with MgB2 composite superconductor is analysed and proposed, including magnet design, test results, and field uniformity. [ABSTRACT FROM AUTHOR]

HTS bulks can be used as flux-focusing elements in reluctance motors. As parts of the primary study, a small prototype reluctance motor was designed and constructed by using HTS YBCO bulks. The performance was analyzed based on magnetic field calculation. An experimental investigation was carded out on the prototype motor. Computed parameters are compared with test measurements, showing good agreement. Compared with the conventional synchronous reluctance motors, higher efficiency and smaller size make these motors very attractive for the applications, such as cryogenic pumps and flywheel drives. [ABSTRACT FROM AUTHOR]

In-situ high-pressure energy dispersive X-ray diffraction measurements on CuBa2-Ca3Cu4O10+δ(Cu-1234) have been performed by using diamond anvil cell (DAC) device with synchrotron radiation. The results suggest that the crystal structure of Cu-1234 superconductor is stable under pressures up to 34 GPa at room temperature. According to the Birch-Murnaghan equation of state, the bulk modulus is obtained to be ∼150 GPa. [ABSTRACT FROM AUTHOR]